As a result of his admissions in a magazine story this week, Florida prosecutors are investigating whether former National Football League player Don Reese violated his probation by using cocaine.

Reese spent a year in jail for selling cocaine to undercover agents in 1977 and is now on probation. If charged and convicted of probation violation, Reese would face a maximum sentence of 15 years, Janet Reno, Dade County state's attorney, said yesterday.

"That is correct," Reno said in a telephone interview. "I wouldn't want to react on the basis of a magazine article, but he could be sent back to jail if we can prove it (that Reese violated his probation). An investigation has already started."

Reese, 30, described his own experiences with the drug in the June 14 issue of Sports Illustrated, and alleged that its use has been widespread among many players on the Miami Dolphins, New Orleans Saints and San Diego Chargers. Reese spent part of the 1981 season with the Chargers but was released late in the season. He said in the article he is undergoing rehabilitation in a hospital and will not play football again.

Reese and then-teammate Randy Crowder of the Miami Dolphins were arrested in May 1977. They were sentenced by Judge Joseph Durant to one year in the Dade County Stockade. Both were released on probation at the same time. The probation expires in August.

Durant told the Miami Herald that Reese's statements in the magazine were "a shock."

"If the man has been doing what the story says he has been doing, I would give him the maximum penalty," Durant said. "That's what I told him I would do. That's what I promised him if he violated his probation.

"One of the conditions is that you do not violate the law. It's against the law to possess cocaine," said Durant, who last year was transferred to juvenile court.

In New Orleans, Mike Strachan, a former running back for the Saints, was indicted Wednesday by a federal grand jury in New Orleans on seven cocaine charges. U.S. Attorney John Volz said Wednesday he wanted to talk to Reese about drug use by Saints players as part of a grand jury investigation.

Volz said the investigation has shown there are "a substantial number of present and former (Saints) players who have used cocaine. Most have not."

In the magazine piece, Reese wrote that early in the 1980 season he had telephoned Charles R. Jackson, assistant director of security for the NFL who handles drug-related issues. Reese, then playing for the Saints, wrote that he "realized we needed help. Players were in the streets at night, going from house to house, getting stuff."

According to Reese, Jackson wasn't available when he called. He was told Jackson would call back, but Reese said the call was not returned.

NFL Commissioner Pete Rozelle, in a prepared statement, said yesterday, "The only telephone conversation between Don Reese and this office was to Charles Jackson in the fall of 1980 after Reese had been suspended by the New Orleans Saints for his altercation with (defensive lineman) Derland Moore during a practice session. The conversation involved his contractual status and he was told the Saints were acting within their rights in suspending him. There was no mention of medical assistance.

"Contrary to players being 'rebuffed,' the league and its member clubs now emphasize to players, as part of official NFL policy, a confidential medical assistance program regarding drugs and alcohol abuse, and to this date 17 players have undergone rehabilitation treatment."

Rozelle was not in his office yesterday. An NFL spokesman said only, "That is his statement. He's not going to say any more."

Gene Klein, owner of the Chargers, issued a statement Wednesday calling Reese's allegation that San Diego has a big drug problem "ludicrous."

Klein told Associated Press, "We're not claiming we're lily-white . . . there's no question in my mind that pro athletes are using narcotics and chemicals, just as other parts of our society are. Our policy has been to help anyone who comes forward. But we can't be their keepers."

Reese, who played in Miami from 1974 to 1976, also alleged that as many as half of the 1976 Dolphins used cocaine. In a telephone interview, Miami Coach Don Shula said, "I just refuse to believe anything like that. I realize now there had to be some (cocaine) involvement, because Reese and Crowder were arrested. But I wasn't ever conscious of any drug use. In our meetings and practices, I'd be the first to notice (a problem)."

Shula said his reaction to the 1977 arrest of Reese and Crowder was "astonishment."

"When I saw it on the TV news, I was just stunned," he said. "I have been very proud of our teams and all they have accomplished. And I would not accuse or indict them on what Reese says."